Imagine never having to put on a fitness-tracking device again because all the sensors you need are embedded in your clothes. Athos Works Inc. not only imagined it, the company made it real.

Athos makes smart compression shirts for men and women, shorts for men, and capri-style pants for women that are the next wave of performance apparel. They measure a variety of data about your heart, lungs, and muscles as you work out, counting your sets and reps, and showing you in real time how hard your muscles are working.

Team members from Athos invited me to a gym in New York to try on a pair of the capris before they are released to the public.

I was greeted with a pair of capris that felt heavier than typical Dri-FIT wear, but seemed much more durable.

Fitting Into Athos's Capris"We ask that you have nothing on underneath," co-founders Dhananja Jayalath (he goes by D.J.) and Jake Waxenberg told me.

"Nothing?" I asked.

"The sensors need to make contact with the skin. And there are two sensors in the rear."

I paused, and with a straight face said, "So I'm good in a thong. Right?" Such conversations do not typically take place in my line of work.

I headed into a changing room and pulled on the pants. They hit my mid calves, and I really worked to get them all the way on, like a wetsuit. While not nearly as thick as neoprene, the sensation of putting on the garment is similar.

When I stepped out, Jake and D.J. already had an app pairing up to see what my muscles were doing.

"Oh. Those are too big. You need to go down a size. The sensors need to be right against the skin."

Back into the changing room, I wiggled my way into a medium. As I've learned from previous wearables, fit matters!

Sensors and CalibrationThe mediums worked much better, as all the sensors were receiving information. The capris for women (and shorts for men), have EMG, or electromyography, sensors that measure electrical activity produced by skeletal muscles. In the bottoms, they track both the left and right side of the glueteus, inner quadriceps, outer quadriceps, and hamstrings. Two additional sensors measure heart rate.

All the information collected by the sensors is sent to a core, or central device, that snaps into the pants on one side. That core then relays the data it collects to a Bluetooth-connected phone, where you can see it in a mobile app.

With a snug pair of pants now watching my muscles, it was time for a quick calibration exercise. All I had to do was walk up a flight of stairs at a slightly slower-than-normal pace while holding a smartphone. The app told me when to stop. The pants and app calibrated in mere seconds. Impressive.

Smarty Pants WorkoutNow that I was all suited up and calibrated, I was eager to work out.

The app shows two outlines of a human body, one facing front and the other turned around. I squeezed by butt. The buttox on the second figure flashed blue. "Woah," I said. I squeezed just my left cheek, then right. They flashed, left right, pulsing along with my beat. "This is so cool."

I lunged, squatted, and kicked my legs. Muscles on the body in the app flashed again, different colors showing different levels of exertion.

D.J. told me to do five squats. I did. The pants and app counted my five squats, and then generated a report showing that I favored my left leg. "Try it again, and try to do it more evenly now." I did. It worked.

We moved next to a squat machine, where one might assume that the body will be better balanced as a result of being, you know, in a machine. I pulled off another five squats and looked at my results. I was still favoring that left leg and not engaging my right glute at all. I did a few more reps, this time watching the app while I squatted, and had the ability to adjust my form in real time to better equalize the weight.

D.J. looked at my progress and said, "You can handle more weight."

"Well," I hemmed and hawed, "I don't want to overdo it."

"If you can jump, you can squat more than your body weight," he said, and I added another 40 pounds to the machine.

It was harder, but not too hard. D.J. and Waxenberg looked at the app results and agreed. I could handle even more. My hamstrings, quads, and glutes were only flashing blue and yellow. I still had to get to green and red. When it's too much weight, the muscles flash white.

That kind of instant feedback that is specific to my body is incredible. If a personal trainer told me I could handle more weight safely, I would say, "You are not me, feeling this weight. And I don't want to hurt myself. It feels like too much. No." The Athos pants and app, however, said, "We know based on objective data that your muscles are doing just fine, and if it becomes too much weight, we'll let you know."

We moved around the gym hitting other leg weight machines. Same deal. I could instantly see which of my muscles were engaging, which were taking the brunt of the exercise. All the while, the app was recording my heart rate, total workout time, and sets and reps for each exercise.

I hopped on a stationary bike, easily the machine I feel most comfortable using. Instantly, Waxenberg noticed that I wasn't pedal-mashing, meaning I was using my muscles correctly to cycle. I quickened my pace. The muscles shown in the app continued to light up just as fast I could pedal, with no delay whatsoever.

AmazedSince wrapping up my workout with the Athos capris, I've been debating whether to reserve a pair for $99, plus $199 for core, before they become publicly available. Early adopters don't actually pay anything until the garment ships in late November.

I'm even more curious about the shirt, which the team says isn't quite ready to demo just yet. My legs are in decent shape, but I could stand to do some strength-training on my top half, and I really like the idea of getting objective data from EMG sensors much more than working with a trainer. The shirt will measure the left and right side each of the trapezius, deltoids, pectoralis, biceps, and triceps; plus it will have two for heart rate sensors and two sensors near the lungs to track breathing. When the shirt does become available, it will likely cost $99 as well, and you'll need a core for it, too.

Athos, and most other smart clothing in development, reportedly holds up in the washing machine like any other poly-blend wicking clothing. Just don't put them in the dryer. I'll let you know if that's the case when I get a pair in to test more thoroughly later this year.

About the Author

Jill Duffy is a contributing editor, specializing in productivity apps and software, as well as technologies for health and fitness. She writes the weekly Get Organized column, with tips on how to lead a better digital life. Her first book, Get Organized: How to Clean Up Your Messy Digital Life is available for Kindle, iPad, and other digital forma... See Full Bio

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